Prop for mines.



0. GRNBWALD 6r M. GORIGH.

PROP FOR MINES.

APPLIOATION FILED rms. 1a, 1911.

Patented Mar. 26, 1912.

a @M www UNITED sTATEs PATENT oEEIoE.

OTTO GRNEWALD AND MAX GORICH, OF EHRENFELD, NEAR COLOGNE, GERMANY.

PROP FOR MINES.

Specification of Letters Patent.

Application led February 18, 1911.

Patented Mar. 26, 1912.

Serial No. 609,527.

To all whom t may concern Be it known that we, OTTO GRNEWALD and MAX GORICH, subjects of the Emperor of Germany, residing at Ehrenfeld, near Cologne, in the Pro-vince of Rhineland, Germany, have invented certain new and useful Improvements in Props for Mines, of which the following is a specification.

This invention relates to props which support the roof in mines, tunnels and other excavations; and it consists in the novel construction and combination of the parts hereinafter fully described and claimed.

In the drawings, Figure l is a side view of a prop constructed according to this invention. Fig. 2 is a side view of the base drawn to a larger scale. Fig. 3 is a plan view of the base.

The base el is tubular in form and it has slots d in its sides.

E is a shaft which is j ournaled in the bottoms of the slots d and which has an eccentric e secured on its middle part inside the base. An operating handle g engages with a rectangular projection g on the projecting end portion of the shaft, and this handle or llever may be removed from the shaft at wil A plate f is arranged to slide in the base al over the eccentric, and a, is a tubular prop section which rests on the said plate and which is also slidable vertically in the base.

The prop section a is provided with a telescopic extension b which is slidable in it, and` b is a conical chamber at the top of the prop section a. Balls c are arranged in the annular space between the wall of the chamber b and the prop section a, and these balls prevent the prop section b from sliding downward but permit it to be raised.

The prop is fitted to the mine or excavation by sliding the telescopic section upward until the prop fits between the roof and floor, and the eccentric is then turned upward so as to jam the prop tightly and thereby secure it in place.

lVhat we claim is:

In a prop, the combination, with a base adapted to rest on the ground and having 'a tubular guide provided with slots in its sides, of a shaft adapted to be dropped into the said slots and to revolve in their bottom ends, said shaft having an eccentric on its middle part and a rectangular projection on one end, a removable operating lever for engaging with the said projection, and a prop section slidable in the said guide and adapted to be raised and clamped in position by the said eccentric.

In testimony whereof we have affixed our signatures, in presence of two witnesses.

oTTo GRNEWALD. MAX GOEICH.

Vitnesses OTTO KRAMER, LOUIS VANDORY.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents. Washington, D. G. 

